Electric feeler control for machine tools



J 19444 EJF. MULLER 2,351,626

ELECTRIC FEELER comaoL .FOR MACHINE TOOLS I Filed Aug. 3, 193a a Sheets-Sheet 1 INYENTOR. 00 420 FEL/X MULLER.

June 20, 1944. E MULLER 2,351,626

ELECTRIC 'FEELER CONTROL FOR MACHINE'TOOLS Filed Aug. 3, @938 8 Sheets-Sheet 2 LONG! TUB/NAZ- FEED Mo 70/? VE/e TICAL F550 Mara/a I INVENTOR. 00 490 FAz/X M0245? ATTORNEYS.

. June'2 0,1 944. ELF. MULLER ELECTRIC FEELE-R CONTROL FOR MACHINE TOOLS Filed Aug. 3, 1938 8 Sheets-Sheet 3 [DU/4P0 F54 /x MZ/L LEE.

June 20,1944. MULLER I 2,351,626

' ELECTRIC FEELER CONTROL FOR MACHINE TOOLS Filed Aug. 3, 1938 8 Sheets-Sheet 4 I [am/21) FELIX M01453.

June 20, 1944. i UL 2,351,626

' ELECTRIC FEELER CONTROL FOR MACHINE TOOLS Filed Aug. 3, 1938 8 Sheets-Shegt 5 INVENTOR. 00AA 0 Fez/x MULLER.

June 20, 1944. E. F. MULLER 2,351,626

ELECTRIC FEELER CONTROL FOR MACHINE TOOLS Filed Aug. 3, 1938 8 Sheets-Sheet 6 INVENTOR. Eoumao FELIX MULLER.

(M-3M fin-"5 ATTORNEYS.

.June 20,1944. MULLER 2,3s1,'e2s

ELECTRIC FEELER CONTROL FOR MACHINE TOOLS Filed Aug. a, 1938 s Sheets-Sheet 7 i uana;

INYENTOR. 00,4 0 Fez/x MULLER.

A TTOR/VHS.

J'uneZO, 1944. E. F. MULLER ELECTRIC FEELER CONTROL FOR MACHINE TOOLS Filed Aug. 3, 1938 8 Sheets-Sheet 8 1NVENTOR,- fez/A20 Fez/x Mayra.

A T TORJVE Y5? Patented June 20, 1944 ELECTRIC FEELER OONTROLVFOR MACHINE TOOLS Eduard Felix Miiller, Leipzig, Germanyi vested in the Alien Property Custodian Application August 3, 1938, Serial No. 222,743" In Germany January'14,'1936 a 12 Claims. (Cl.9ll13.5) I This invention relates to electric feeler controls of machine tools for cutting a work piece in accordance with a pattern so as to obtain an exact duplicate of the pattern.

If the feeler control is mounted upon an existing milling machine, the milling cutter is fixed in the usual way on the milling machine spindle, and the guide sleeve is firmly clamped in the milling spindle head, so that the cutter assumes a fixed position, thus not being movable in the direction of the spindle axis. The feeler device is rigidly attached to the head-piece by means of a connecting arm and hence maintains a fixe spatial relation to the cutting tool. 1

. The feed of the feeler occurs in the direction of thespindle axis. means of spindles, bevel wheels, worm and worm wheels. The guide feed is retained in the normal manner, but a friction coupling and a locking brake are provided, which, influenced by an oscillating switch, come into operation at a given moment and lock the longitudinal feed. Both movements, control in height and longitudinal feed, are separately derived each from an electric motor.

Two feeding movements are effective in the machining process, namely, the feeler feed and the pilot or guide feed. The feeler feed occurs in a .direction to and from the object to be machined, while the guide feed moves longitudinally with respect to the object, i. e. at right angles to the feeler feed.

With larger types of machines, the feeler feed movement is preferably located in the milling movement is'controlled in dependence upon the extent of the path traversed by the feeler. When operating with such a control, many closely adjacent points of the pattern are felt off and this closeness is adjustable by an oscillating switch and is dependent upon the choice of the speed of feed.

The movements of the feeler are: (1) Towards the pattern, (2) After contact with the :pattem,.

therefrom,

(3) After leaving the pattern, again towards it. By means of this feeler-which represents a influenced that a spot shaped and exact feeling off is possible.

Machines to be provided with this control must permit a reversal of the main cutting feed so as to perform a reciprocating feed movement and also he provided foran adjustment of the feeding stroke. Thelmachines must'also allow effecting a subsidiary feed movement which occurs by a definite amount transverse to the main feed movement after each reciprocation.

According to a more specificaspect of the in- Ventiomthe contour milling is effected by means This control is effected by of two round tables which are fixed to an angle iron at' rig'ht angles to the working table and are mounted on the working tableand are driven in the same way by a sliding shaft which i in connection with a locking brake and friction coupling. Abevel gearing connected with the guide sleeveof the milling spindle permits the milling cutter to function inthehorizon'tal position and hence to permit the contour milling. This araway . double position switch, the control circuits are so rangement is particularly suitable for machining dies fordrop presses and for the plastics industry or the like, and for the contour milling of cam discs corresponding to sheet metaltemplates.

The feeler is conveyed line by line over the surface of the pattern, and accordingly the tool over the workpiece Atthe end of each cut, a lateral forward movement or feed occurs equal to the width of a cut. The cutting movement takes place in the vertical direction and the stepwise feed forward in the'horizontal direction.

. In order that the present invention may be clearly understood anexample of the general design, construction and manner of operation will be described with reference to the accompanying drawings, in which: i

Fig. 1 is a front elevation of a machine tool;

Fig. 2 is a side view of themachine shown in Fig;

Fig. 3 is asectional plan view on line 3-3 Fig.1 showing the control with reversing gear and the transmission of the control movement to the lifting shaft;

Fig. 4 is a sectionahplanviewon line 4-4 Fig. 1 showing the introductionof the control movement by the liftingshaft up to the bracket spindle and the oscillating switch arrangement;

Fig. 5 shows the. oscillatory switch partly in section;

Fig. 6 is a sectional view of the drive and locking of the longitudinal feed taken on line 6- 6 in Fig.2;

Fig. 7 shows the locking brake with brake mag.- net;

Fig. 8 is a sectional plan view of the driving mechanism parts for the movement of the table taken on line 8-8 Fig. 1; r

Fig. 9 shows the device for contour milling from sheet metal templates;

Fig. 9a is a sketch showing the manner of contour milling without the round table;

Fig. 10-shows the drive of the round table;

Fig. 11 is a vertical section through the feeler in larger scale;

Fig. 12 shows the circuit diagram for threephase current operation with a reversing mo-' tor for operating the milling machine;

Fig. 13 is the circuit diagram for three-phase current operation with reversing gear;

Fig. 14 shows in greatly enlarged scale asecto be cut out and the table 8 to be shifted manually.

In parallel to the current circuit which influences the vertical feed reversing motor l2, an oscillating switch 40 l4 (Figs. 4 and 5) is actuated which controls the current circuit of a locking magnet .25 (Figs. 6 and. 7) which is required for locking the longitudinal feed. The drive for the longitudinal feed is effected from a motor 26 (Figs. 2 and 6) which drives from a --multi+stepped pulley 2! by way of a similarly stepped pulley 28 a worm gear 29 located in a tion through a portion of the rough machined article; and

Fig. 15 shows a similar section through the ar ticle duringthe finishing process.

The machine itself is a normal milling machine (Figs. 1 and 2) Itsstationary frame comprises a' pedestal I and a headpiece 2. Onthe headpiece 2 is'mounted a motor carrier 3 which supports amilling motor l. This motor 4 drives a milling spindle 1 by means of abelt 5 and a stepped pulley B. The machine is also provided with a support structure for accommodatinga work piece and a pattern. The support is composed of a vertically movable main table 8, a cross slide 9 mountedc'thereon, a work table mounted to travel longitudinally on slide 9;and on which table the workpiece A-is clamped, and

a pattern table n fixed on table In andwhich ing-themillingoperation, a-contact 13 shown; in

Fig. ll'is opened and closed, this contact controlling the vertical movement. According to thisoperating principle the pattern B, fixed on table VI 0, approaches and recedes from a feeler 66 described in more detail below, and which con-,

trolsthe contact'l3'so that the current circuit of the. contact 13 is closed when the feeler touches thepattern 13 and :is; opened again during the 'return movementof table. In and soon. By

means of-thisopening and closingof the .'cur-.- rent circuit, there "isacontrolled through an auxiliary relay. l6. (Figs.';12 and 1.3) a reversing. relay 1'! which influences a reversing motor I 2:: (Figs. 1, 2 and 12) in such=a manner that clockwise or counterclockwise rotation thereof is suddenly initiated. I

In order to protect the motor l2 from excessive heating, a protective resistance 18 (Figs. 12 and 13) is provided in each phase. The reversing movement is transmitted from the moto r' l2 through a coupling l3 (Fig. 1) onto a. lower worm gear M; whichis supported in a lower oscillatingly disposed housing l5 (Figs. 1; 2 and 3).. A rising shaft 16 transmits the movement to 'an upper worm gear I! (Figs. 1, 2 and 4) which is located in an upper oscillatingly disposedhous ing I8. By means of two bevel wheels' l9; the movement is then transmitted to a bracketsp indle 20 threaded into abracket spindle nut 2!. In this manner, the upward and downward movement of the main'table 8 is attained.

In'order that the vertical table 8 may also be moved manually, a bevel wheel shaft 22"'(Fig." 4) is provided with a handwheel23. In the upper tilting housing ill a claw coupling 24 is mounted worm bearing housing 38. The movement is transmitted to a cone clutch 3| (Fig. 6), which by means of a nut 32 and a spring 33 can be adjusted to 'a particular torque. A ratchet wheel 34 (see also Fig. 7) having straight rectangular teeth is keyed to the clutch core 3|, so that looking can occur in both directions of. rotation since the reversal of. the workingtable" Ill is elfectedbythe motor26. H

'The reversal is effected electrically. Stop earns 35 (Figs. 1, 2 and 12) which are fixedion the working tableflfi press against push knobs 36 of a push button switch 31 which is' screwed onto the cross slide 9. In this way-a reversing relay l9 (Figs. 12 and 13) is influenced and the motor 28 is correspondingly reversed inpolarity and thus changes its direction of rotation.

A'locking lever 38 (Figs, 7, l2 and1'3) in the form of a double-armed lever is set in operation after the locking, by a magnet 25. If the magnet 25 is tie-energized, the locking lever '38- is drawn back by a spring--39 and the longitudinal feed again comes into operation. "The oscillating switch dd43-is driven by means of the bevel wheels 19 and shaft 22 from'the bracket spindle 20-which causes the table Ill to oscillatevertically. As long as the feeler touches a level surface on the pattern, the oscillatingswitch lever dlfwhichis carried along by a cone clutch 4| (Figs: 4 and 5) actuated by the spring 42 and adjustable nut 43', oscillates between two contacts 44 and 45 only to a limited extent'and without touching-them. Even, however, inmachining a level surface, the contact systems 44 and can be touched, and this in the finishing and for increasing the accuracy. During the normalbackward and forward oscillation of the ward and forward on the cross slide 9.

which permits the automatic vertical movement If the feeler pin 66, however, comes to a depression inthe pattern of such dimensions that the extent'o-f the previous rising movement of the table, which occurs only with a level surface, is exceeded, then the oscillating switch 1ever 48 performs an extended oscillation and thereby strikes against the contact -44 or' 45, closes the currentcircuit of the locking magnet 25, so that the lock 34 and 38 comes into operation and stops the longitudinal feed until the feeler pin 66 abuts against the bottom of the depression. The table Ill thereupon immediately commences the return movement downwardly and the oscillating switch lever 40 then interrupts the contact 44 or 45 which has just been closed and the locking magnet 25 is de-energiz'ed. The return spring 39 (Figs. 7,12and 13) unlocks the longitudinal feed and the working taable Hi again resumes its longitudinal movement.

' The contact 45 (Figs. 4 and 5) of the oscillating switch 4043 is firmly fixed on the table '3. The other contactM is connected to a lever mentwillbe explained below. t v

The automatic longitudinal table movement is transmitted from a clutch coupling shaft 48 (Figs. .6 and 8) onto a telescope shaft 50 through a .universcal joint Y49 and 'from the shaft 50 through a bevelgear and two spur-wheels 52 and 53 onto the table spindle 54. If the working table I0 is to be adjusted in the longitudinal direction manually, it is necessary forthe automatic longitudinal feed to be disengaged. This is effected by means of a coupling lever 55 which takes the spur-wheel 53 and the bevel wheel 51 out of engagement. The table can then be moved manually through a handwheel 56 (Fig; 8) or cranks 56 (as shown in Fig. 1).

On the table bracket 8 is provided a terminal switch 58' (Figs; 1. 12 and 13) which is actuated by .a cam stop 59 adjustably clamped on the cross slide 9. This terminal switch 58 serves to attain. a limited stroke in the transverse direction and to stop the working table It! in any desired adjusted width of cut. As can be seen from the circuit diagrams of Figs. 12 and 13, this terminal switch 58 is electrically in series with the automatic switch in the motor control circuit. so that the terminal switch 58 is in a position to stop the whole machine. v

The feeler is constructed as a double position switch and is normally rigidly connected through a rotatable rod 60 and a connecting arm 6! to the headpiece 2 and thus normally always remains in fixed relation to the milling cutter 62. However the vertical relation between the feeler and the milling cutter 62 isvariable byproviding a movable milling cutter spindle guide sleeve table II by means of a spindle 64 (Fig. 1) with respect to the cross slide 9. I a

The feeler-consists of a disc 65 (Fig. 11) having a central stud carrying the interchangeable feeler pinlifi, which is threaded into it. .Externally, the periphery of disc 65 is ground slightly spherical so as to permit the door to slightly tilt, andso that the feeler can easily glide over slight obstacles; The disc must; however, fit closely into the ring 61. On the flat bottom side, the

disc 65 rests on three set screws 68 threaded into ring 61, whereby the feeler disc is positioned correctly in this ring. On the ring 6'! and over the disc 65 is placed an elastic diaphragm 69 which is clamped near its circumference against ring 61 by a housing III (of insulating material). In the upwardly extending cylindrical portion of housing 10 is provided a bore H which widens downwardly and meets the dome-shaped main chamber of the housing located adjacent to diaphragm 69. (for instance 6 millimetres diameter of the bore at the top and 60.millimetres diameter of the chamberat the bottom gives the square of the ratio as; 10?:190) thengives almost frictionless transmission.

An addi-' The square of the ratio of the diameters Inthe hollow space of housing 10, is located the operating liquid, namely mercury, up to the level shown in Fig. 11. This arrangement'works in a similar manner to the known hydraulic ram,

which converts a small force into a large force.

For with the feeler described, a small movement of the feeler is converted into a .large travel of the displaced mercury in the narrow bore H, so that it can be regarded as a hydraulic travel amplifier. The exact adjustment level is eiiected by screws 68 which are also adjusted to compensate for large temperature differences. If a slight pressure is applied to the feeler pin 66 vertically from below, or laterally, then the displacement causes the mercury to rise in the bore II. By means of the screw 12, current is conveyed into the mercury. In the position of the feeler as shown, the auxiliary relay 15 (Figs. 12 and 13) and the reversing relay I1 are cut out. The pattern B approaches the feeler pin 65 and as soon as mechanical contact is made the mercury rises and contacts with the screw 13 which is also included in the relay circuit. .The auxiliary relay I6 and th'ereversing relay H are energized and the motor I 2 suddenly changes its direction of rotation. The working table l0 now moves away from the. milling cutter 52 and the pattern table I l away from the feeler pin 66, and the mercury again falls below the tip of the screw 13.. The auxiliaryrelay 16 and also the reversing relay 71 are again de-energized. The polarity of the motor-l2 is thereby reversed and the table Ill again riises towards the feeler pin 66, the cycle of operationsybeing repeated. The screws 12 and 13 are provided with hard metal tips. On the failure of any intermediate apparatus, the mercury will rise, as soon as the feeler pin touches the pattern, until the screw M makes contact with the mercury. In this way the quick break release of the protecting switch 15 is set in operation and the entire current supply is cut off. Furthermore, the safety switch is provided -with a bimetal release, so that the machine is also stopped on the occurrence of other faults causedfor instance by racing of the milling spin- .dle on the normal, current being exceeded. The equalization of pressure in the feeler is effected by a widened portion "H of bore H r Instead of providing the reversing motor !2,

the reversing gearcan be operated bya threephase motor [211 (Fig. .3).

which inlthe embodiment with reversing motor 55' The current circuit controlled the reversing relay 11, now controls an electro-magnet which attractsa reversing coupling 8|. Assoon as the current circuit is interrupted, the magnet 80 is deenergized and the spring 82 predominates and reverses the direction of rotation which 'theshaft'83 transmits to the lower worm gear 14 and onto the bracket 8.

Thecontourmilling (Figs.9 andlO) is rendered possible by first setting the milling tool 62 into the horizontal position by substituting another headpiece 63 in which the tool is driven by a bevel wheel drive 85 as shown in Fig. 9. On the working table [0 is clamped an angle bracket 84 which carries two similarly driven round tables 86 and 61. One round table 86 carries the work 'piece, for iristancathe cam disc 88to be milled, and the sheet metal template is laid flat against the other round table 81. A feeler suitable for the horizontal position operates on the sheet metal template. The electric vertical movement ,for the table Hllis maintained tl e samevasyshown in Figs. 1 and 2. "The Iautomaticflongitudinal movement with. the .clutch coupling 3 i 3ii ,and locking device 25, 34' and 38, functions through two toothed wheels .89 and .90' ,on;a:second.te1escope shaft 9| which-\drivesthr'ough two bevel wheels 92 the worm shaft.93 for operating the round tables 86 and 81.

With larger types of machines, the eleotric-control is located inthe transverse movement of the cross slide 9, and itth'uslacts on the transverse spindle 95 (Fig .2) which moves the cross slide, that is, in the horizontal direction. The round tables 86 and 81' arethenarranged horizontally on the workingtable f .andare also driven by the automatic longitudinal movement with. locks '25, at andl38. andsclutch coupling al-gas'.

A reversingswitch .94 .is inserted in the-current circuit in order [that such parts as are actually tobe machined onthe roundtable in the contour milling process, can also be copied on the longitudinal table. The.work-.88 isclamped on the angle bracket 84 (Fig. 9a). Parallel thereto is fixed the sheet..metal template and first of all the upperper'iph eral contour of the template is traced and its contour reproduced on theworkpiece 88 betweenthe two points a, so that the electric vertical movement of the working table occui-s-irombeloW upwards. The reversing switch '94 is then reversed and the lower contour ofT-thetemplate is'traced again between thetWo points a an'd" reproduced on work pieceBB, whereby the electric vertical movement now, however, :occursfrom above downwards. By means of this arrangement, it is not necessary to provide two rotating tables but all similar articles can be .copied in this way.

Finally, the diagrams shown :in Figs. '14 and will be explained.

During rough -machining (Fig. 14 considerable importance is placed on sagreat amount of work and small accuracy. This can, in the first place, be attained-by the selection of a high speed of feed, and 'se'condlvby-the adjustment of the oscillating switch 40 43,in such a man ner that the two contacts 44 and 45 areplaced widely apart so that the longitudinal feed is not interrupted with'the" usual vertical control, and the oscillating switch lever 40 swings backward and forward withouttouching' the contacts 44 and 45, so that it is immaterial'wh'ether the points to be traced are brought quite close together, sincethe locking of-the table'feed commences evenibefore th'eelectricyertical control has terminated. It is thusseen that the'faccuracy is not dependent upon the' cohtactpath and the play of the driving mechanism parts,'but only upon the closeness of the pointsto be traced. This closeness can'be. regulated to any desired small value,'the:-accuracy thus being extremely great.

In the two Figs.-l4and l5jthe'points. to be traced are shown Wide apart for clarity in order that th method of working of thisdescrlbed; arrangement can be ,understood. that-the working tab le l0 'moves from A to B, that is, in the direction of the arrow.

What is claimedis: I

1. An electrically actuatednfeele'r control for machine tools having afeeler disposed inffixed relation to the operating tool offthe machine, an operating table carrying the work piece and the pattern to be copied,me'an s"lor oscillating the pattern and work piece on said table toward and It is assumed away from the feeler and operating tool respectivelylso as to perform almu'ltitude of reciprocations independent of thefcontour of the pattern,

means controlled by the force of the contact between the feelerand the pattern for actuating said. moving ,rneans to remove the table rrqm the pattern and tooiwhen the patterntouches the .feeler and to again reverse the table movement as soon as thefeeler and pattern are. outof contact, separate means for'normally longitudinally reciprocating the operatingv table withina desired range in a direction transversely to thefeelerand operating tool to reproduce point by point ,the pattern contour on the work piece, and means actuated by the movement of saidoperating table toward and away from saidfeeler for-arresting said longitudinaltable jmotion when the feeler passes into a depression ofthe pattern and has oscillated beyond a given range until the .feeler reaches the bottom of saiddepression and has caused the table to recede from the feeler.

2. An electrically ,act uated feeler control for machine tools having a feeler disposed in fixed relation to the operating tool of the machine, an operating table carrying the workpiece and the pattern to be copied, [means for oscillating the pattern and work piece on said table toward and away from the feeler and operating tool respectively so as to perform a multitude of reciprocations independent of the contour of the pattern, means controlled by the force of the contact between the feeler and the pattern for actuating said moving means to remove the table from the pattern and tool when the pattern touches the feeler and to again reverse the table movement as soon as the feeler and pattern areout of contact, separate means for normally longi- ,forroscillating said lever between said contacts angular distances proportional to the oscillat- 'ing distances of said table, and electric control means including said contacts and said lever for stopping said longitudinal table feed when the lever contacts with either contact, so that so long as the table and lever oscillate within ranges in which the lever does not touch its contacts the longitudinal table feed is maintained, but is interrupted when the table performs excessive oscillations in either direction due to deviations of the pattern surface from a given contour line.

3. 'An-electrically 'actuated-feeler control for machinetools having a feeler'disposed in fixed relation to the operating tool of the machine, an operating table carrying the work piece and the pattern to be copied, means for oscillating the pattern and work-piece on said table toward and away from the ieeler and operating tool respectively so as to perform a multitude of reciprocations independent of the contour of the pattern, means controlled by the force of the contact between the feeler and the pattern for. actuating said moving means to remove the table from the pattern and tool when the pattern touches the feeler and to again reverse the table movement as soon as the feeler and pattern are out of contact, separate means fo normally longitudinally reciprocating the operating table within-a desiredrange i'n'a-direction transversel to the feeler and o eratingtool to reproduce point by point the pattern contour on the work piece, two contacts and. an oscillating lever disposed between said contacts Which. are spaced apart to determine a given operating range of oscillating distances of said table, electric cont fQl means including said contacts and said lever for stopping said longitudinal table feed when the lever contacts with either contact, so that so long as the table and lever oscillate within ranges in which the lever does not touchits contacts the, longitudinal table feed is maintained, but is interrupted when the table performs excessive oscillations in either direction due to deviations of the pattern surface from a given contour line, and means for varying the distance between said contacts, V p

4. An electrically actuated feeler control for machine tools having a feeler disposed in fixed relation to the operating tool of the machine, an operating table carrying the work piece and the pattern to be copied, means for oscillating the pattern and work piece on said table toward and away from the feeler and operating tool respectively so as to perform a multitude of reciproca: tions independent of the contour of the pattern, means controlled by the force of the contact between the feeler and the pattern for actuating said moving means to remove the table from the pattern and tool when the pattern touches the feeler and to again reverse the table movement as soon as the feeler and pattern are out of contact, separate means for' normally longitudinally reciprocating the operating'table within a desiredir'ange in a direction transversely to the feeler and operating tool to reproduce point by pointthe pattern contour onthe work piece, two contacts and an oscillating leverdisposed between said contacts which are spaced apart to determine a given operating range of said lever, a sliding-couplin'g connected between said lever and the table oscillating means for oscillating said lever between said contacts angular distances proportionalto the oscillating distances of said table, and electric control means including said contacts and said lever for stopping said longitudinal table feed when the lever contacts with either contact, so that so long as the table and lever oscillate within ranges in which the lever does not touch its contacts the longitudinal table feed is maintained, but is interrupted when the table performs excessive oscillations in either direction due to deviations of the pattern surface from a given contour line. 5. An electrically actuated feeler control for machine tools having a feeler disposed in fixed relation to the operating tool of the machine, an operating table carrying the work piece and the, pattern to be copied, means for oscillating the pattern and work piece on said ,table toward and away from the feeler and operating .tool re} spectively so as to perform a multitude of reciprocatiqns independent of the contour of the pattern, means controlled by the force of the contact between the feeler and the pattern for actuating said moving means to remove the table from the pattern and tool when the pattern touches the feeler and to again reverse the table movement as soon as the feeler and pattern are out of contact, an electric motor for normally longitudinally reciprocating the operating table within a desired range in a direction transversely to the feeler and operating tool to reproduce point by pointthe pattern contour on the work piece, a sliding clutch arranged between said table and said motor, electric means actuated by the movement of said table toward and away from said feeler for arresting said longitudinal table motion when the feeler passes into a depression of the pattern and has oscillated beyond a given range until the feeler reaches the bottom of said depression and has caused the table to recede from the feeler, whereby said sliding clutch yields at the arresting of the longitudinal table motion.

6. An electrically actuated feeler control for machine tools having afeeler disposed in fixed relation to the operating tool of the machine, an operatingtable carrying the work piece and the pattern to be copied, means for producing relative oscillatory motion between the pattern and work piece on said table on one hand and the feeler and operating tool respectively on the other hand so as to perform a multitude of reciprocations independent of the contour of the pattern, means controlled by the force of the contact between the feeler and the pattern for actuating said moving means to separate the table and tool when the pattern touches the feeler and to again reverse this motion as soon as-the feeler and pattern are out of contact, separate means for normally longitudinally reciprocating the operating table within a desired range in a direction transversely to the feeler and operating tool to reproduce point by point the pattern contour on the work piece, and means actuated by the relative to and fro movement between said operating table and said feeler for arresting said longitudinal table motion when the feeler passes into a depression of the patternand has oscillated beyond a given range until the feeler reaches the bottom of said depression and has caused a separation between the pattern and the feeler.

7. In a machine tool for cutting a work piece according to a pattern, the combination of a cutting tool, a touch-controlled feeler member capable of effecting a deflection movement when engaging and disengaging the pattern, said feeler member being arranged in a fixed relation to said tool, actuating means for effecting relative reciprocations between the pattern and the feeler member andbetween the operating tool and the work piece so as to perform a multitude of reciprocations independent of the contour of the pattern, contacts and step-up means associated with said feeler member for transferring said deflection movement into a contact movement of enlarged amplitude, electric control means connected between said contacts and said actuating means for controlling the amplitude of the reciprocations of said actuating means, drive means for eifecting between the pattern and said feeler member and between the Work piece and said tool afeed movement transversal to said reciprocations and unidirectional during a sequence of said reciprocations, arresting means associated with said drive means for interrupting said transversal feed movement, and adjustable control means connected with said reciprocating means for controlling said arresting means to interrupt said transversal feed movement in dependence upon said amplitude of said reciprocations exceeding an adjusted magnitude.

8. In a machine tool for cutting a work piece according to a pattern, the combination of a cutting tool, a feeler member arranged in a fixed relation to said tool and consisting of an electric touch-controlled two-position contactor movable relative to the pattern tobe copied so as to be actuated when engaging and disengaging the pattern, power-operated means for effecting relative reciprooations between'the pattern and the ieeler member andbetween'the operating tool and the" work piece so" as to perform a multitude of reciprocations independent of the contour of the pattern, electric circuit meansbonnected'btween said contactor andsaid'reciprocating means'for varying the amplitude of said reciprocations in dependence upon the actuation of said contactor by said pattern, power operated drive means for eiiecting between the'fpattern and said ieefler member and between the, work piece and said tool'a feed movementtransversal to said reciprocations and unidirectional'during a sequence of said reciprocation's, arresting means associated with said drive means for interrupting said transversal feed movement, and adjustable control means connected with said reciprocatingmeans for controllingsaid' arresting means 'to interrupt said transversal feed movement in "dependence upon said amplitude "of said reciprocations exceeding an adjusted magnitude.

9. Ina machine tool ior'cutting a work piece according to a'patterm'the Combination of a cutting tool, a feeler member arranged in a fixed relation to said tool and consisting of a touchcontrolled electriccontactor movable relative to the pattern to be copied so as'to 'beactuated when engaging and disengaging the pattern, power-operated means foreiiecting relative reciprocations between the "pattern and the ieeler member and between the operatingto'ol and'the work piece so as to perform a multitude of refciprocations independentof the'contour of the pattern, electriccircuit means connected between said contactor and said reciprocating means for varying the amplitude of said reciprocations in dependence upon the actuation of said contactor by said pattern, power-operated drive means for effecting between the'pat'tern and said feeler member and between the work piece and said tool a'feed movement transversal tosaid r'ecipro cations and unidirectionalduring a sequence of said reciprocations, arresting means associated withsaid drive means for interrupting said transversal feedmovement, a device for measuring the magnitude of said amplitude ofsaid'reciprocations', said device having a'movable member and contacts adjustably arranged in'the path of said movable member, a mechanism'forming part of said reciprocating means and said device for imparting to said movable member a proportionallyenlarged amplitude as c-omparedwith that of said reciprocations of said contactor relative to said pattern, and an electric control circuit connected between said measuring device and said arresting means for controlling" said arresting means to interrupt said transversal feed move ment in dependenceupon said movable member engaging said adjustableco'ntacts;

10. In amachine tool for cutting a work piece according to a pattern, the combination of a support for accommodating the work piece and the pattern; a cutting tool, a touch-controlled feeler member to be actuated by engagement with said pattern, said feeler' member being arranged in a fixed relation to said cutting tool, poweroperated actuating means controlled by said feeler for reciprocating said support so as to effect an oscillatory motion between said pattern and said feeler member and between said work piece and said tool, reversible fdrive meansfor producing a transversal feeding movement'oi adjustable rate of feed and of uniform direction during periods comprising an adjustable u -1 er, means for producing a relative oscillatory.

feed movement between said feeler and saidtool on' the one hand and said pattern and 'sa'id work piece on the'other hand, means for sup r: posing to said reciprocatory 'feed 'movementan intermittent progressive guide feed at" "a right angle to said reciprocatory feed so as to efie'ct a resultant relative feed movement betweensai'd tool and said work piece along a steppedwork' ing curve, said touch-responsive feeler having a contact device with only two operative cosy-1 tact positions for directly controlling said reciprocatory feed, and control means independ-; ent of said contact device for controlling-said intermittent guide feed in dependence upontlie reciprocatory feeler feed movement. I

12..In a'machine tool having a' pattern, and a tool for cutting a work piece when towards 'the workpiece according to the'pat} tern, in combination, a touch-responsive,ieeler, means for producing an oscillatory relative feed movement between said feeler and saidftodl on the one hand and said pattern and said work piece on the other hand, means forv 'superposing to said reciprocatory feed movement an intermitjf tent progressiveguidefeed ata rightfa ngle to said reciprocatory feed movement so as t'l efiect a resultant relative feed movement between said tool and said work piece along asteppedwork; ing curve, said touch-responsive feeler havinga contact device with only two operative contact positions fordirectly controlling said alter t ing feed, and control means independ ento said contact device for controlling said intermittent guide feed independence upon said toohb out of engagement with said work piece, whereby said work piece iscut according to said pattern by a multitude of cutting operations occurring during the strokes towards said work piece; oi?

said reciprocatory feed movement.

EDUARD FELI 

